In general, a plasticizer is prepared by esterification reaction between an acid and an alcohol. Examples of catalysts commonly used for esterification reaction include organometallic compounds including titanium compounds, tin compounds and the like, ion exchange resins, zeolite, heteropolyacids, sulfuric acid, para-toluene sulfonic acid and the like.
There are differences in reaction rate and production of by-products between these catalysts due to characteristics of the respective catalysts. An esterification reaction for plasticizer synthesis is performed using an optimal catalyst selected while taking these points into consideration. This catalyst is selected in view of reaction velocity as well as ease of removal and process stability during purification. In reality, solid catalysts have an advantage in that purification of products through simple filtering is simplified in the purification process and homogeneous catalysts have an advantage of an increased rate of reaction. However, esterification reaction is performed using optimal catalysts selected in consideration of all circumstances.
Recently, upon selection of catalysts, attempts to develop and apply catalysts capable of securing an eco-friendly preparation process are made and research associated therewith is underway.
Catalyst development focuses on increase in rate of reaction, minimization of by-products and simplification of purification processes. There is a need for continuous research, which secures optimal plasticizer synthesis conditions while increasing rate of reaction and preventing effects of by-products on product quality, when various catalysts are used.